Journal of Tissue Viability RSS feed: Articles in Press. The Journal of Tissue Viability is the official publication of the Tissue Viability Society and is a quarterly journal concerned with all aspects of the occurrence and treatment of wounds, ulcers and pressure sores including patient care, pain, nutrition, wound healing, research, prevention, mobility, social problems and management. The Journal particularly encourages papers covering skin and skin wounds but will consider articles that discuss injury in any tissue. Articles that stress the multi-professional nature of tissue viability are especially welcome. We seek to encourage new authors as well as well-established contributors to the field - one aim of the journal is to enable all participants in tissue viability to share information with colleagues.http://www.journaloftissueviability.com//inpress?rss=yesElsevier Inc.en © 2009 Tissue Viability Society. All rights reserved. Journal of Tissue Viability0965-206X2010-02-12 © 2009 Tissue Viability Society. All rights reserved. healthpermissions@elsevier.comhttp://www.journaloftissueviability.com/article/PIIS0965206X09000667/abstract?rss=yesAbstract: People with spinal cord injuries are at high risk for developing pressure ulcers. Increased skin temperature is one of the extrinsic causative factors for this multi-factorial disease. Previous animal studies revealed that local skin cooling reduced the severity of ulceration, and cooling is widely used in plastic surgery and organ transplants for tissue preservation. The objectives of this pilot study were to develop test protocols and instrumentation and to investigate the effect of local cooling on skin perfusion response to pressure on young healthy human subjects. Reactive hyperemia was quantified in this study to compare the effects of pressure with and without cooling. Reactive hyperemia is a normal physiological response occurring after vessel occlusion. Laser Doppler flowmetry was used to measure skin blood flow. Time-dependent spectral analysis was used to analyze and decompose the blood flow data into frequency ranges associated with specific blood flow control mechanisms. The study used a repeated measures design with two test conditions: 8kPa of pressure with and without cooling to 25°C. We hypothesized that local cooling would reduce the post-ischemic reactive hyperemic response induced by the rigid indenter. Time series results showed that normalized peak perfusion response was significantly lower with cooling (p=0.019). Time-dependent spectral analysis results suggested that both metabolic and myogenic responses contribute to this protective effect. Findings from our study on humans were consistent with previous animal studies. Additional studies on individuals with spinal cord injury are planned to further evaluate the cooling effect in a high-risk population.Effects of local cooling on sacral skin perfusion response to pressure: Implications for pressure ulcer prevention - Corrected ProofYi-Ting Tzen, David M. Brienza, Patricia Karg, Patrick Loughlin10.1016/j.jtv.2009.12.003Journal of Tissue Viability (2010)2010-02-12Journal of Tissue Viability2010-02-12http://www.journaloftissueviability.com/article/PIIS0965206X0900062X/abstract?rss=yesAbstract: Introduce a reliable stowage by means of syringe to preserve split-thickness-skin grafts.A reliable stowage by means of syringe for preserving split-thickness-skin grafts - Corrected ProofYu-Yin Wang, Ji-Yong He, Xiao-Ping Liu, Xiao-Fang Li10.1016/j.jtv.2009.10.005Journal of Tissue Viability (2010)2010-01-20Journal of Tissue Viability2010-01-20CLINICAL STUDYhttp://www.journaloftissueviability.com/article/PIIS0965206X09000588/abstract?rss=yesAbstract: Risk assessment scales are widely used to measure the risk of pressure ulcers in the clinical area. They have been subject to many validation studies; however these have focused on the predictive ability of the scales.We have conducted several studies that consider the validity of pressure ulcer risk assessment scales. We have reviewed these and revisited the data in some cases to conduct additional tests of validity presented for the first time in this paper.Based on these results, and a review of the literature, we have come to the conclusion that while the scales are probably reliable, and do assess risk:The complexity of risk assessment scales does not appear to be warranted. There is evidence that clinical judgment is as effective in assessing risk as risk assessment scales. Reduction in pressure ulcer incidence after implementation of risk assessment tools is likely to be an example of the Hawthorn effect.We believe risk assessment scales are useful research tools, but may not be useful in clinical practice.Do risk assessment scales for pressure ulcers work? - Corrected ProofDenis Anthony, Panos Papanikolaou, Sam Parboteeah, Mohammad Saleh10.1016/j.jtv.2009.11.006Journal of Tissue Viability (2009)2009-12-25Journal of Tissue Viability2009-12-25REVIEWhttp://www.journaloftissueviability.com/article/PIIS0965206X09000552/abstract?rss=yesAbstract: Some implications from a simplified finite-element model are given in this study. The model takes into account the sequential steps of wound contraction, angiogenesis and wound closure. An innovation in the present study is the combination of these partially overlapping processes, yielding novel insights into the process of wound healing, such as geometry related influences, and could be used to investigate the influence of local injection of hormones that stimulate partial processes occurring during wound healing. These insights can be used to improve wound-healing treatments. The model consists of nonlinearly coupled diffusion–reaction and visco-elastic equations, in which transport, production and decay of oxygen, growth factors and various cell types. The present paper provides results of the healing of deep wounds under several regimes of endothelial and epithelial cell migration, and the results are interpreted in a biological sense.Computer simulations from a finite-element model for wound contraction and closure - Corrected ProofF.J. Vermolen, E. Javierre10.1016/j.jtv.2009.11.003Journal of Tissue Viability (2009)2009-12-21Journal of Tissue Viability2009-12-21CLINICAL STUDYhttp://www.journaloftissueviability.com/article/PIIS0965206X09000606/abstract?rss=yesAbstract: This short review summarizes the localization and effects of the plant lectin soybean agglutinin (SBA) on the injured and non-injured organ-cultured rat corneal endothelium. Although the tissue exists as a non-cycling monolayer on the posterior corneal surface a circular freeze injury promotes wound repair as cells initiate DNA synthesis, mitosis and migration. As a result, by 24 h post-injury, endothelial cells express a surface protein that binds SBA in a diffuse punctate pattern, which by 48 h after injury, becomes confined to the cell periphery. As healing proceeds, SBA binding dramatically declines, such that, only scattered binding is observed by 72 h after wounding. In non-injured organ-cultured endothelia, weak SBA binding appears 24 h after explanation but becomes prominently detected around the cell periphery by 48 h. Incubating injured or non-injured endothelia in SBA leads to alterations in their cellular appearance due to the fact that lectin exposure results in the disruption of the actin cytoskeleton. Although this does not affect migration, treatment with either SBA or N-acetylgalactosamine (the SBA binding sugar) does interfere with the reestablishment of cell–cell contact. It is postulated that the surface protein that binds SBA is expressed during conditions that are stressful to the tissue. During organ-culture the protein's appearance suggests a cellular response to explantation in order to enhance or maintain monolayer integrity. In wound repair its appearance may serve to establish preliminary cell–cell contact during the restoration of the endothelial monolayer.The effects of soybean agglutinin binding on the corneal endothelium and the re-establishment of an intact monolayer following injury – A short review - Corrected ProofSheldon R. Gordon10.1016/j.jtv.2009.11.008Journal of Tissue Viability (2009)2009-12-21Journal of Tissue Viability2009-12-21REVIEWhttp://www.journaloftissueviability.com/article/PIIS0965206X09000540/abstract?rss=yesAbstract: For pressure ulcer prevention an ambitious goal would be the establishment of a mechanical threshold for tissue damage. In the past, several researchers have sought to establish such a threshold often involving the loading time. However, they have not resulted in a unique reliable value that could be used in practice. This limitation is probably due to the focus on interface pressure. The objective of this paper is to clarify to an audience with no conventional background in mechanics, why interface pressure is not the appropriate parameter to define a damage threshold, whereas internal local deformations (strains) may prove more suitable. The paper reveals that it may be possible to identify a damage threshold for healthy skeletal muscle tissue based on local internal deformations.The importance of internal strain as opposed to interface pressure in the prevention of pressure related deep tissue injury - Corrected ProofC.W.J. Oomens, Sandra Loerakker, D.L. Bader10.1016/j.jtv.2009.11.002Journal of Tissue Viability (2009)2009-12-14Journal of Tissue Viability2009-12-14CLINICAL STUDYhttp://www.journaloftissueviability.com/article/PIIS0965206X09000576/abstract?rss=yesAbstract: Loss of adipose tissue can occur due to congenital and acquired lipoatrophies, trauma, tumor resection, and chronic disease. Clinically, it is difficult to regenerate or reconstruct adipose tissue. The extensive microvsacular network present in adipose, and the sensitivity of adipocytes to hypoxia, hinder the success of typical tissue transfer procedures. Materials that promote the formation of vascularized adipose tissue may offer alternatives to current clinical treatment options. A number of synthetic and natural biomaterials common in tissue engineering have been investigated as scaffolds for adipose regeneration. While these materials have shown some promise they do not account for the unique extracellular microenvironment of adipose. Adipose derived hydrogels more closely approximate the physical and chemical microenvironment of adipose tissue, promote preadipocyte differentiation and vessel assembly in vitro, and stimulate vascularized adipose formation in vivo. The combination of these materials with techniques that promote rapid and stable vascularization could lead to new techniques for engineering stable, vascularized adipose tissue for clinical application. In this review we discuss materials used for adipose tissue engineering and strategies for vascularization of these scaffolds.Clinical Relevance: Materials that promote formation of vascularized adipose tissue have the potential to serve as alternatives or supplements to existing treatment options, for adipose defects or deficiencies resulting from chronic disease, lipoatrophies, trauma, and tumor resection.Materials for engineering vascularized adipose tissue - Corrected ProofYu-Chieh Chiu, Ming-Huei Cheng, Shiri Uriel, Eric M. Brey10.1016/j.jtv.2009.11.005Journal of Tissue Viability (2009)2009-12-14Journal of Tissue Viability2009-12-14CLINICAL STUDYhttp://www.journaloftissueviability.com/article/PIIS0965206X09000618/abstract?rss=yesAbstract: Many rat/mouse pressure ulcer (PU) models have been developed to test different hypotheses to gain deeper understanding of various causative risk factors, the progress of PUs, and assessing effectiveness of potential treatment modalities. The recently emphasized deep tissue injury (DTI) mechanism for PU formation has received increased attention and several studies reported findings on newly developed DTI animal models. However, concerns exist for the clinical relevance and validity of these models, especially when the majority of the reported rat PU/DTI models were not built upon SCI animals and many of the DTI research did not simulate well the clinical observation. In this study, we propose a rat PU and DTI model which is more clinically relevant by including chronic SCI condition into the rat PU model and to simulate the role of bony prominence in DTI formation by using an implant on the bone–tissue interface. Histological data and imaging findings confirmed that the condition of chronic SCI had significant effect on pressure induced tissue injury in a rat PU model and the including a simulated bony prominence in rat DTI model resulted in significantly greater injury in deep muscle tissue. Further integration of the SCI condition and the simulated bony prominence would result a rat PU/DTI model which can simulate even more accurately the clinical phenomenon and yield more clinically relevant findings.Deep tissue injury rat model for pressure ulcer research on spinal cord injury - Corrected ProofFang Lin, Atek Pandya, Andrew Cichowski, Mauli Modi, Briana Reprogle, Dongkeun Lee, Norio Kadono, Mohsen Makhsous10.1016/j.jtv.2009.11.009Journal of Tissue Viability (2009)2009-12-14Journal of Tissue Viability2009-12-14CLINICAL STUDYhttp://www.journaloftissueviability.com/article/PIIS0965206X0900059X/abstract?rss=yesWe are pleased to present this Special Issue on Bioengineering in Tissue Viability to the readership of the journal. Challenges in preventing and treating chronic wounds create one of the most important areas of unsolved medical problems, impacting the life of many, decreasing the quality of life of many others, and costing billions in each country. Chronic wounds affect diverse but at the same time large patient populations, such as those with neuromuscular injuries and diseases, diabetes or geriatric patients. Considering that the size of the elderly population is continuously increasing, and that the number of newly diagnosed diabetes cases is climbing up throughout the Western world, the scale of tissue viability related problems is projected to grow even greater in the near future. Unfortunately, until recently, wounds in soft tissues received relatively little attention from the bioengineering research community.Bioengineering research in tissue viability - Corrected ProofAmit Gefen, Laura E. Edsberg10.1016/j.jtv.2009.11.007Journal of Tissue Viability (2009)2009-12-11Journal of Tissue Viability2009-12-11EDITORIALhttp://www.journaloftissueviability.com/article/PIIS0965206X09000564/abstract?rss=yesAbstract: Fibroblasts are one of the most abundant cell types in connective tissues. These cells are responsible for tissue homeostasis under normal physiological conditions. When tissues are injured, fibroblasts become activated and differentiate into myofibroblasts, which generate large contractions and actively produce extracellular matrix (ECM) proteins to facilitate wound closure. Both fibroblasts and myofibroblasts play a critical role in wound healing by generating traction and contractile forces, respectively, to enhance wound contraction. This review focuses on the mechanisms of force generation in fibroblasts and myofibroblasts and techniques for measuring such cellular forces. Such a topic was chosen specifically because of the dual effects that fibroblasts/myofibroblasts have in wound healing process– a suitable amount of force generation and matrix deposition is beneficial for wound healing; excessive force and matrix production, however, result in tissue scarring and even malfunction of repaired tissues. Therefore, understanding how forces are generated in these cells and knowing exactly how much force they produce may guide the development of optimal protocols for more effective treatment of tissue wounds in clinical settings.Fibroblasts and myofibroblasts in wound healing: Force generation and measurement - Corrected ProofBin Li, James H.-C. Wang10.1016/j.jtv.2009.11.004Journal of Tissue Viability (2009)2009-12-08Journal of Tissue Viability2009-12-08BASIC RESEARCHhttp://www.journaloftissueviability.com/article/PIIS0965206X09000539/abstract?rss=yesAbstract: Wound dressings aim to restore the milieu required for skin regeneration by protecting the wound from environmental threats, including penetration of bacteria, and by maintaining a moist healing environment. A wide variety of wound dressing products targeting various types of wounds and different aspects of the wound healing process are currently available on the market. Ideally, a dressing should be easy to apply and remove, and its design should meet both physical and mechanical requirements; namely water absorbance and transmission rate, handleability and strength. In this article, our novel biodegradable antibiotic-eluting wound dressings are described and the engineering aspects in the design are emphasized. These unique new wound dressings are based on a polyglyconate mesh, coated with a porous Poly(dl-lactic-co-glycolic acid) matrix. They demonstrated excellent mechanical and physical properties and desired release profiles of antibiotic drugs which enable bacterial inhibition. Hence, a new generation of wound dressings is now emerging with clear benefits. These include better protection against infection and reducing the need for frequent dressing changing.Novel antibiotic-eluting wound dressings: An in vitro study and engineering aspects in the dressing's design - Corrected ProofJonathan J. Elsner, Meital Zilberman10.1016/j.jtv.2009.11.001Journal of Tissue Viability (2009)2009-12-07Journal of Tissue Viability2009-12-07http://www.journaloftissueviability.com/article/PIIS0965206X09000382/abstract?rss=yesAbstract: Aim: The achievement of a well-healed wound depends on many factors including its size and location on the body and the properties of the skin. The aim of this study is to develop computational wound closure models and compare the results of using different excision shapes.Methods: Finite element models were developed that simulated the incision, excision and closure of skin. Skin was represented by an orthotropic constitutive law. The size of extrusions, maximum stresses and the force to close wounds with differently shaped excisions were analysed.Results: Circular excisions resulted in closed wounds with extrusion heights 76% larger than fusiform or lazy S-plasty excisions. The extrusion length for circular excisions was 50% longer than the lazy S-plasty extrusion length. The maximum stresses around closed wounds with elliptical excisions were between 30 and 40% lower than the maximum stresses around fusiform and lazy S-plasty closed wounds. The force required to close an elliptical wound was between 27 and 66% lower than the closure force of fusiform and lazy S-plasty excisions. The orthotropic nature of skin and the orientation of the excision significantly influence the behaviour of the skin around the closed wound. The in vivo pre-stress, often ignored in wound closure models, influences the size of extrusions. Increasing the pre-stress by a factor of twenty decreased extrusion heights by 40%. A similar change in pre-stress decreased extrusion lengths by 50%.Conclusion: These models have potential as valuable clinical tools to determine the optimum excision shape that will minimise adverse stress fields and reduce scarring. Models that are patient-specific would be useful to design strategies to ensure favourable healing and improve the quality of life of the person.Finite element models of wound closure - Corrected ProofCormac Flynn10.1016/j.jtv.2009.10.001Journal of Tissue Viability (2009)2009-11-30Journal of Tissue Viability2009-11-30CLINICAL STUDY